diff --git a/src/c/cmpaux.d b/src/c/cmpaux.d
index 682f6b352..3e4664da0 100644
--- a/src/c/cmpaux.d
+++ b/src/c/cmpaux.d
@@ -216,6 +216,12 @@ cl_parse_key(
     FEprogram_error("Odd number of keys", 0);
   if (ecl_unlikely(unknown_keyword != OBJNULL && !allow_other_keys &&
                    (supplied_allow_other_keys == ECL_NIL ||
-                    supplied_allow_other_keys == OBJNULL)))
+                    supplied_allow_other_keys == OBJNULL))) {
+    for (i = 0; i < nkey; i++) {
+      if (keys[i] == @':allow-other-keys' && vars[nkey+i] == ECL_T && !Null(vars[i])) {
+        return;
+      }
+    }
     FEprogram_error("Unknown keyword ~S", 1, unknown_keyword);
+  }
 }